summaryrefslogtreecommitdiffstats
path: root/gfx/cairo/libpixman/src/pixman-trap.c
diff options
context:
space:
mode:
Diffstat (limited to 'gfx/cairo/libpixman/src/pixman-trap.c')
-rw-r--r--gfx/cairo/libpixman/src/pixman-trap.c711
1 files changed, 711 insertions, 0 deletions
diff --git a/gfx/cairo/libpixman/src/pixman-trap.c b/gfx/cairo/libpixman/src/pixman-trap.c
new file mode 100644
index 0000000000..7560405ee2
--- /dev/null
+++ b/gfx/cairo/libpixman/src/pixman-trap.c
@@ -0,0 +1,711 @@
+/*
+ * Copyright © 2002 Keith Packard, member of The XFree86 Project, Inc.
+ * Copyright © 2004 Keith Packard
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of Keith Packard not be used in
+ * advertising or publicity pertaining to distribution of the software without
+ * specific, written prior permission. Keith Packard makes no
+ * representations about the suitability of this software for any purpose. It
+ * is provided "as is" without express or implied warranty.
+ *
+ * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "pixman-private.h"
+
+/*
+ * Compute the smallest value greater than or equal to y which is on a
+ * grid row.
+ */
+
+PIXMAN_EXPORT pixman_fixed_t
+pixman_sample_ceil_y (pixman_fixed_t y, int n)
+{
+ pixman_fixed_t f = pixman_fixed_frac (y);
+ pixman_fixed_t i = pixman_fixed_floor (y);
+
+ f = DIV (f - Y_FRAC_FIRST (n) + (STEP_Y_SMALL (n) - pixman_fixed_e), STEP_Y_SMALL (n)) * STEP_Y_SMALL (n) +
+ Y_FRAC_FIRST (n);
+
+ if (f > Y_FRAC_LAST (n))
+ {
+ if (pixman_fixed_to_int (i) == 0x7fff)
+ {
+ f = 0xffff; /* saturate */
+ }
+ else
+ {
+ f = Y_FRAC_FIRST (n);
+ i += pixman_fixed_1;
+ }
+ }
+ return (i | f);
+}
+
+/*
+ * Compute the largest value strictly less than y which is on a
+ * grid row.
+ */
+PIXMAN_EXPORT pixman_fixed_t
+pixman_sample_floor_y (pixman_fixed_t y,
+ int n)
+{
+ pixman_fixed_t f = pixman_fixed_frac (y);
+ pixman_fixed_t i = pixman_fixed_floor (y);
+
+ f = DIV (f - pixman_fixed_e - Y_FRAC_FIRST (n), STEP_Y_SMALL (n)) * STEP_Y_SMALL (n) +
+ Y_FRAC_FIRST (n);
+
+ if (f < Y_FRAC_FIRST (n))
+ {
+ if (pixman_fixed_to_int (i) == 0xffff8000)
+ {
+ f = 0; /* saturate */
+ }
+ else
+ {
+ f = Y_FRAC_LAST (n);
+ i -= pixman_fixed_1;
+ }
+ }
+ return (i | f);
+}
+
+/*
+ * Step an edge by any amount (including negative values)
+ */
+PIXMAN_EXPORT void
+pixman_edge_step (pixman_edge_t *e,
+ int n)
+{
+ pixman_fixed_48_16_t ne;
+
+ e->x += n * e->stepx;
+
+ ne = e->e + n * (pixman_fixed_48_16_t) e->dx;
+
+ if (n >= 0)
+ {
+ if (ne > 0)
+ {
+ int nx = (ne + e->dy - 1) / e->dy;
+ e->e = ne - nx * (pixman_fixed_48_16_t) e->dy;
+ e->x += nx * e->signdx;
+ }
+ }
+ else
+ {
+ if (ne <= -e->dy)
+ {
+ int nx = (-ne) / e->dy;
+ e->e = ne + nx * (pixman_fixed_48_16_t) e->dy;
+ e->x -= nx * e->signdx;
+ }
+ }
+}
+
+/*
+ * A private routine to initialize the multi-step
+ * elements of an edge structure
+ */
+static void
+_pixman_edge_multi_init (pixman_edge_t * e,
+ int n,
+ pixman_fixed_t *stepx_p,
+ pixman_fixed_t *dx_p)
+{
+ pixman_fixed_t stepx;
+ pixman_fixed_48_16_t ne;
+
+ ne = n * (pixman_fixed_48_16_t) e->dx;
+ stepx = n * e->stepx;
+
+ if (ne > 0)
+ {
+ int nx = ne / e->dy;
+ ne -= nx * (pixman_fixed_48_16_t)e->dy;
+ stepx += nx * e->signdx;
+ }
+
+ *dx_p = ne;
+ *stepx_p = stepx;
+}
+
+/*
+ * Initialize one edge structure given the line endpoints and a
+ * starting y value
+ */
+PIXMAN_EXPORT void
+pixman_edge_init (pixman_edge_t *e,
+ int n,
+ pixman_fixed_t y_start,
+ pixman_fixed_t x_top,
+ pixman_fixed_t y_top,
+ pixman_fixed_t x_bot,
+ pixman_fixed_t y_bot)
+{
+ pixman_fixed_t dx, dy;
+
+ e->x = x_top;
+ e->e = 0;
+ dx = x_bot - x_top;
+ dy = y_bot - y_top;
+ e->dy = dy;
+ e->dx = 0;
+
+ if (dy)
+ {
+ if (dx >= 0)
+ {
+ e->signdx = 1;
+ e->stepx = dx / dy;
+ e->dx = dx % dy;
+ e->e = -dy;
+ }
+ else
+ {
+ e->signdx = -1;
+ e->stepx = -(-dx / dy);
+ e->dx = -dx % dy;
+ e->e = 0;
+ }
+
+ _pixman_edge_multi_init (e, STEP_Y_SMALL (n),
+ &e->stepx_small, &e->dx_small);
+
+ _pixman_edge_multi_init (e, STEP_Y_BIG (n),
+ &e->stepx_big, &e->dx_big);
+ }
+ pixman_edge_step (e, y_start - y_top);
+}
+
+/*
+ * Initialize one edge structure given a line, starting y value
+ * and a pixel offset for the line
+ */
+PIXMAN_EXPORT void
+pixman_line_fixed_edge_init (pixman_edge_t * e,
+ int n,
+ pixman_fixed_t y,
+ const pixman_line_fixed_t *line,
+ int x_off,
+ int y_off)
+{
+ pixman_fixed_t x_off_fixed = pixman_int_to_fixed (x_off);
+ pixman_fixed_t y_off_fixed = pixman_int_to_fixed (y_off);
+ const pixman_point_fixed_t *top, *bot;
+
+ if (line->p1.y <= line->p2.y)
+ {
+ top = &line->p1;
+ bot = &line->p2;
+ }
+ else
+ {
+ top = &line->p2;
+ bot = &line->p1;
+ }
+
+ pixman_edge_init (e, n, y,
+ top->x + x_off_fixed,
+ top->y + y_off_fixed,
+ bot->x + x_off_fixed,
+ bot->y + y_off_fixed);
+}
+
+PIXMAN_EXPORT void
+pixman_add_traps (pixman_image_t * image,
+ int16_t x_off,
+ int16_t y_off,
+ int ntrap,
+ const pixman_trap_t *traps)
+{
+ int bpp;
+ int height;
+
+ pixman_fixed_t x_off_fixed;
+ pixman_fixed_t y_off_fixed;
+ pixman_edge_t l, r;
+ pixman_fixed_t t, b;
+
+ _pixman_image_validate (image);
+
+ height = image->bits.height;
+ bpp = PIXMAN_FORMAT_BPP (image->bits.format);
+
+ x_off_fixed = pixman_int_to_fixed (x_off);
+ y_off_fixed = pixman_int_to_fixed (y_off);
+
+ while (ntrap--)
+ {
+ t = traps->top.y + y_off_fixed;
+ if (t < 0)
+ t = 0;
+ t = pixman_sample_ceil_y (t, bpp);
+
+ b = traps->bot.y + y_off_fixed;
+ if (pixman_fixed_to_int (b) >= height)
+ b = pixman_int_to_fixed (height) - 1;
+ b = pixman_sample_floor_y (b, bpp);
+
+ if (b >= t)
+ {
+ /* initialize edge walkers */
+ pixman_edge_init (&l, bpp, t,
+ traps->top.l + x_off_fixed,
+ traps->top.y + y_off_fixed,
+ traps->bot.l + x_off_fixed,
+ traps->bot.y + y_off_fixed);
+
+ pixman_edge_init (&r, bpp, t,
+ traps->top.r + x_off_fixed,
+ traps->top.y + y_off_fixed,
+ traps->bot.r + x_off_fixed,
+ traps->bot.y + y_off_fixed);
+
+ pixman_rasterize_edges (image, &l, &r, t, b);
+ }
+
+ traps++;
+ }
+}
+
+#if 0
+static void
+dump_image (pixman_image_t *image,
+ const char * title)
+{
+ int i, j;
+
+ if (!image->type == BITS)
+ printf ("%s is not a regular image\n", title);
+
+ if (!image->bits.format == PIXMAN_a8)
+ printf ("%s is not an alpha mask\n", title);
+
+ printf ("\n\n\n%s: \n", title);
+
+ for (i = 0; i < image->bits.height; ++i)
+ {
+ uint8_t *line =
+ (uint8_t *)&(image->bits.bits[i * image->bits.rowstride]);
+
+ for (j = 0; j < image->bits.width; ++j)
+ printf ("%c", line[j] ? '#' : ' ');
+
+ printf ("\n");
+ }
+}
+#endif
+
+PIXMAN_EXPORT void
+pixman_add_trapezoids (pixman_image_t * image,
+ int16_t x_off,
+ int y_off,
+ int ntraps,
+ const pixman_trapezoid_t *traps)
+{
+ int i;
+
+#if 0
+ dump_image (image, "before");
+#endif
+
+ for (i = 0; i < ntraps; ++i)
+ {
+ const pixman_trapezoid_t *trap = &(traps[i]);
+
+ if (!pixman_trapezoid_valid (trap))
+ continue;
+
+ pixman_rasterize_trapezoid (image, trap, x_off, y_off);
+ }
+
+#if 0
+ dump_image (image, "after");
+#endif
+}
+
+PIXMAN_EXPORT void
+pixman_rasterize_trapezoid (pixman_image_t * image,
+ const pixman_trapezoid_t *trap,
+ int x_off,
+ int y_off)
+{
+ int bpp;
+ int height;
+
+ pixman_fixed_t y_off_fixed;
+ pixman_edge_t l, r;
+ pixman_fixed_t t, b;
+
+ return_if_fail (image->type == BITS);
+
+ _pixman_image_validate (image);
+
+ if (!pixman_trapezoid_valid (trap))
+ return;
+
+ height = image->bits.height;
+ bpp = PIXMAN_FORMAT_BPP (image->bits.format);
+
+ y_off_fixed = pixman_int_to_fixed (y_off);
+
+ t = trap->top + y_off_fixed;
+ if (t < 0)
+ t = 0;
+ t = pixman_sample_ceil_y (t, bpp);
+
+ b = trap->bottom + y_off_fixed;
+ if (pixman_fixed_to_int (b) >= height)
+ b = pixman_int_to_fixed (height) - 1;
+ b = pixman_sample_floor_y (b, bpp);
+
+ if (b >= t)
+ {
+ /* initialize edge walkers */
+ pixman_line_fixed_edge_init (&l, bpp, t, &trap->left, x_off, y_off);
+ pixman_line_fixed_edge_init (&r, bpp, t, &trap->right, x_off, y_off);
+
+ pixman_rasterize_edges (image, &l, &r, t, b);
+ }
+}
+
+static const pixman_bool_t zero_src_has_no_effect[PIXMAN_N_OPERATORS] =
+{
+ FALSE, /* Clear 0 0 */
+ FALSE, /* Src 1 0 */
+ TRUE, /* Dst 0 1 */
+ TRUE, /* Over 1 1-Aa */
+ TRUE, /* OverReverse 1-Ab 1 */
+ FALSE, /* In Ab 0 */
+ FALSE, /* InReverse 0 Aa */
+ FALSE, /* Out 1-Ab 0 */
+ TRUE, /* OutReverse 0 1-Aa */
+ TRUE, /* Atop Ab 1-Aa */
+ FALSE, /* AtopReverse 1-Ab Aa */
+ TRUE, /* Xor 1-Ab 1-Aa */
+ TRUE, /* Add 1 1 */
+};
+
+static pixman_bool_t
+get_trap_extents (pixman_op_t op, pixman_image_t *dest,
+ const pixman_trapezoid_t *traps, int n_traps,
+ pixman_box32_t *box)
+{
+ int i;
+
+ /* When the operator is such that a zero source has an
+ * effect on the underlying image, we have to
+ * composite across the entire destination
+ */
+ if (!zero_src_has_no_effect [op])
+ {
+ box->x1 = 0;
+ box->y1 = 0;
+ box->x2 = dest->bits.width;
+ box->y2 = dest->bits.height;
+ return TRUE;
+ }
+
+ box->x1 = INT32_MAX;
+ box->y1 = INT32_MAX;
+ box->x2 = INT32_MIN;
+ box->y2 = INT32_MIN;
+
+ for (i = 0; i < n_traps; ++i)
+ {
+ const pixman_trapezoid_t *trap = &(traps[i]);
+ int y1, y2;
+
+ if (!pixman_trapezoid_valid (trap))
+ continue;
+
+ y1 = pixman_fixed_to_int (trap->top);
+ if (y1 < box->y1)
+ box->y1 = y1;
+
+ y2 = pixman_fixed_to_int (pixman_fixed_ceil (trap->bottom));
+ if (y2 > box->y2)
+ box->y2 = y2;
+
+#define EXTEND_MIN(x) \
+ if (pixman_fixed_to_int ((x)) < box->x1) \
+ box->x1 = pixman_fixed_to_int ((x));
+#define EXTEND_MAX(x) \
+ if (pixman_fixed_to_int (pixman_fixed_ceil ((x))) > box->x2) \
+ box->x2 = pixman_fixed_to_int (pixman_fixed_ceil ((x)));
+
+#define EXTEND(x) \
+ EXTEND_MIN(x); \
+ EXTEND_MAX(x);
+
+ EXTEND(trap->left.p1.x);
+ EXTEND(trap->left.p2.x);
+ EXTEND(trap->right.p1.x);
+ EXTEND(trap->right.p2.x);
+ }
+
+ if (box->x1 >= box->x2 || box->y1 >= box->y2)
+ return FALSE;
+
+ return TRUE;
+}
+
+/*
+ * pixman_composite_trapezoids()
+ *
+ * All the trapezoids are conceptually rendered to an infinitely big image.
+ * The (0, 0) coordinates of this image are then aligned with the (x, y)
+ * coordinates of the source image, and then both images are aligned with
+ * the (x, y) coordinates of the destination. Then these three images are
+ * composited across the entire destination.
+ */
+PIXMAN_EXPORT void
+pixman_composite_trapezoids (pixman_op_t op,
+ pixman_image_t * src,
+ pixman_image_t * dst,
+ pixman_format_code_t mask_format,
+ int x_src,
+ int y_src,
+ int x_dst,
+ int y_dst,
+ int n_traps,
+ const pixman_trapezoid_t * traps)
+{
+ int i;
+
+ return_if_fail (PIXMAN_FORMAT_TYPE (mask_format) == PIXMAN_TYPE_A);
+
+ if (n_traps <= 0)
+ return;
+
+ _pixman_image_validate (src);
+ _pixman_image_validate (dst);
+
+ if (op == PIXMAN_OP_ADD &&
+ (src->common.flags & FAST_PATH_IS_OPAQUE) &&
+ (mask_format == dst->common.extended_format_code) &&
+ !(dst->common.have_clip_region))
+ {
+ for (i = 0; i < n_traps; ++i)
+ {
+ const pixman_trapezoid_t *trap = &(traps[i]);
+
+ if (!pixman_trapezoid_valid (trap))
+ continue;
+
+ pixman_rasterize_trapezoid (dst, trap, x_dst, y_dst);
+ }
+ }
+ else
+ {
+ pixman_image_t *tmp;
+ pixman_box32_t box;
+ int i;
+
+ if (!get_trap_extents (op, dst, traps, n_traps, &box))
+ return;
+
+ if (!(tmp = pixman_image_create_bits (
+ mask_format, box.x2 - box.x1, box.y2 - box.y1, NULL, -1)))
+ return;
+
+ for (i = 0; i < n_traps; ++i)
+ {
+ const pixman_trapezoid_t *trap = &(traps[i]);
+
+ if (!pixman_trapezoid_valid (trap))
+ continue;
+
+ pixman_rasterize_trapezoid (tmp, trap, - box.x1, - box.y1);
+ }
+
+ pixman_image_composite (op, src, tmp, dst,
+ x_src + box.x1, y_src + box.y1,
+ 0, 0,
+ x_dst + box.x1, y_dst + box.y1,
+ box.x2 - box.x1, box.y2 - box.y1);
+
+ pixman_image_unref (tmp);
+ }
+}
+
+static int
+greater_y (const pixman_point_fixed_t *a, const pixman_point_fixed_t *b)
+{
+ if (a->y == b->y)
+ return a->x > b->x;
+ return a->y > b->y;
+}
+
+/*
+ * Note that the definition of this function is a bit odd because
+ * of the X coordinate space (y increasing downwards).
+ */
+static int
+clockwise (const pixman_point_fixed_t *ref,
+ const pixman_point_fixed_t *a,
+ const pixman_point_fixed_t *b)
+{
+ pixman_point_fixed_t ad, bd;
+
+ ad.x = a->x - ref->x;
+ ad.y = a->y - ref->y;
+ bd.x = b->x - ref->x;
+ bd.y = b->y - ref->y;
+
+ return ((pixman_fixed_32_32_t) bd.y * ad.x -
+ (pixman_fixed_32_32_t) ad.y * bd.x) < 0;
+}
+
+static void
+triangle_to_trapezoids (const pixman_triangle_t *tri, pixman_trapezoid_t *traps)
+{
+ const pixman_point_fixed_t *top, *left, *right, *tmp;
+
+ top = &tri->p1;
+ left = &tri->p2;
+ right = &tri->p3;
+
+ if (greater_y (top, left))
+ {
+ tmp = left;
+ left = top;
+ top = tmp;
+ }
+
+ if (greater_y (top, right))
+ {
+ tmp = right;
+ right = top;
+ top = tmp;
+ }
+
+ if (clockwise (top, right, left))
+ {
+ tmp = right;
+ right = left;
+ left = tmp;
+ }
+
+ /*
+ * Two cases:
+ *
+ * + +
+ * / \ / \
+ * / \ / \
+ * / + + \
+ * / -- -- \
+ * / -- -- \
+ * / --- --- \
+ * +-- --+
+ */
+
+ traps->top = top->y;
+ traps->left.p1 = *top;
+ traps->left.p2 = *left;
+ traps->right.p1 = *top;
+ traps->right.p2 = *right;
+
+ if (right->y < left->y)
+ traps->bottom = right->y;
+ else
+ traps->bottom = left->y;
+
+ traps++;
+
+ *traps = *(traps - 1);
+
+ if (right->y < left->y)
+ {
+ traps->top = right->y;
+ traps->bottom = left->y;
+ traps->right.p1 = *right;
+ traps->right.p2 = *left;
+ }
+ else
+ {
+ traps->top = left->y;
+ traps->bottom = right->y;
+ traps->left.p1 = *left;
+ traps->left.p2 = *right;
+ }
+}
+
+static pixman_trapezoid_t *
+convert_triangles (int n_tris, const pixman_triangle_t *tris)
+{
+ pixman_trapezoid_t *traps;
+ int i;
+
+ if (n_tris <= 0)
+ return NULL;
+
+ traps = pixman_malloc_ab (n_tris, 2 * sizeof (pixman_trapezoid_t));
+ if (!traps)
+ return NULL;
+
+ for (i = 0; i < n_tris; ++i)
+ triangle_to_trapezoids (&(tris[i]), traps + 2 * i);
+
+ return traps;
+}
+
+PIXMAN_EXPORT void
+pixman_composite_triangles (pixman_op_t op,
+ pixman_image_t * src,
+ pixman_image_t * dst,
+ pixman_format_code_t mask_format,
+ int x_src,
+ int y_src,
+ int x_dst,
+ int y_dst,
+ int n_tris,
+ const pixman_triangle_t * tris)
+{
+ pixman_trapezoid_t *traps;
+
+ if ((traps = convert_triangles (n_tris, tris)))
+ {
+ pixman_composite_trapezoids (op, src, dst, mask_format,
+ x_src, y_src, x_dst, y_dst,
+ n_tris * 2, traps);
+
+ free (traps);
+ }
+}
+
+PIXMAN_EXPORT void
+pixman_add_triangles (pixman_image_t *image,
+ int32_t x_off,
+ int32_t y_off,
+ int n_tris,
+ const pixman_triangle_t *tris)
+{
+ pixman_trapezoid_t *traps;
+
+ if ((traps = convert_triangles (n_tris, tris)))
+ {
+ pixman_add_trapezoids (image, x_off, y_off,
+ n_tris * 2, traps);
+
+ free (traps);
+ }
+}